Questions tagged [odds-ratio]
A measure of association between two binary variables equal to the odds of a 'positive' outcome in 1 variable divided by the odds in the other. The OR ranges (0, infinity). It has a strong connection to logistic regression.
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Vertical translation of independent variable vs OR and independent variable vs RR curve
i have been trying to predict risk of developing a cancer from genetic data. At the end I plotted a curve, that shows odds ratio (OR) and relative risk (RR) as a function of polygenic risk score (PRS) ...
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What is the difference between standardized mortality ratio (SMR) and odds ratio (OR) from age matched case and controls?
My question refers specifically to comparisons of chronic diseases, say heart failure (HF), between a specific group of interest (eg, diabetics) and a reference group (non-diabetics).
SMR is the ...
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Odds Ratio Interpretation and Predicted Probabilities
I am conducting research on the association between smoking and Tuberculosis (TB), and I need to clarify what the odds ratio is telling me. I am getting the Odds Ratio value from the table of a ...
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Generate odds ratios across deciles / quantiles of an indpendent variable
With reference to the following figure from Bellomo et al., 2011:
How exactly are the odds ratios across the deciles 'referenced against the 4th decile' calculated?
My initial impression is that a ...
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Derivation of variance of Odds Ratio in a 2x2 table
Assuming that the elements of a 2x2 table (a,b,c,d) are binomial in distribution with a being $Bin(n_1,p_1)$ and c being $Bin(n_2,p_2)$. How can we show that $\hat {var(logOR)} = \frac 1 a + \frac 1 b ...
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How to interpret odds ratio with continuous independent variable (%) that have categories in different columns?
I am using a logistic regression to model a 0/1 event with community characteristics as being my explanatory variables but my data structure is different making the interpretation hard.
My unit of ...
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Interpreting Odds Ratios for non-binary outcomes [duplicate]
I'm looking to interpret odds ratios with a quaternary outcome.
Specifically, I'm trying to predict students' ratings of fairness (ordinal from Likert scale, 0-3) on a particular exam, based on the ...
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Interpreting odds ratios in ordinal logistic regression
I am trying to predict exam performance (below, average, above) based on whether participants attended a revision class. I am analysing my data in R using a proportional odds logistic regression. I am ...
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When Can I say odds ratio is important to analyze my data
Lets say in my data if I generate odds ratio between 2 variable A and B and get that the odds ratio is 2-5 is that a good thing to dive deep further or should I move to other relations .
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High odds ratio for composite score created by ridge regression
This question is a follow up to one of my previous questions asked on this site. The goal was to create a composite score for biomarkers related to a binary outcome and then use that in a regression ...
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Use example to explain odds ratio to layperson audience
I found an example of how to express odds-ratios in plain english. Here is the link http://www.pitt.edu/~bertsch/risk.pdf
It says:
How does one express an OR of 0.15 in plain English. Had this ...
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Interpreting a very small odds ratio when the Fisher's exact test is significant
I'm having a hard time interpreting odds ratios (OR) for a 2x2 contingency table.
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Group level effects (odds ratio) - dummy coding vs. effect
I ran a logistic model in R's brms, with a categorical variable (condition) with two levels as predictor. When interpreting the ...
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Log odds Standard Error
I am reading a paper on how the authors calculate the variance/standard deviation of what appears to be log(odds).
The paper is a medical paper (Discontinuation of Oral Antivirals in Chronic ...
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Correct interpretation of odds ratio
I am wondering what the correct way of interpreting an odds ratio is. For example, suppose we have that the probability of success is $p=0.8$. Then, the odds ratio is:
$$
\frac{p}{1-p} = \frac{0.8}{0....
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Odd Ratios Change After Including Other Independent Variables… What does that exactly mean?
I am currently writing my master's thesis and I want to identify whether Austrians living in Vienna are more likely than immigrants in Vienna to become self-employed. In order to find out whether this ...
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How to interpret multinomial regression results? [duplicate]
I want to investigate the relationship between stock traders' past success rate (i.e. the number of total winning trades divided by the total trades executed) on the status of their current trading ...
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When to exponentiate: the mean of the chain or at every step in the chain?
I am interested in when it is best to exponentiate a difference in log-odds
Here is a sample problem in the stan language, three groups of forty binary observations, group 1 with hit probability = 0....
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Interpreting odd's ratios
If A is a binary faction (1 A and 0 not A) and if the odds ratios of A to B is (say) 1.2409 (24 percent or e ^ 0.2158). Then is the odds ratio of B to A 76% or 1 – 0.24?
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Odds ratio confidence intervals and p-values suggest different conclusions in a binary logistic mixed-effects model (glmer)
I am running a generalized linear mixed-effects model in R using the glmer function of lme4. The outcome variable is trial-level accuracy in a task (incorrect trials are 0, correct trials are 1), and ...
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Effect size in linear mixed models
Thank you for reading this question.
I know there have been a few discussions regarding this topic, but I couldn't get a satisfactory answer. So here is my question, with some details in the ...
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Baffled by inconsistency between 95% CI for OR and p-value
I am using logistic regression to model the effect of two production variables on the occurrence of tuberculosis. My independent variables are A (farm size: 0 for small, 1 for large) and B (cattle co-...
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Ratio as independent variable for logistic regression
I am trying to model the association between "previous 2 year history of no shows for consult (independent variable)" with current no shows (dependent variable) using a logistic regression model.
The ...
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Convert odds ratio back to logit - logistic regression
I'm attempting to convert odd's ratios reported in results back to their original logit form. From what I've gathered, the appropriate formula to do so is:
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Does the “divide by 4 rule” give the upper bound marginal effect?
In the logisitic regression chapter of "Data Analysis Using Regression and
Multilevel/Hierarchical Models" by Gelman and Hill, The "Divide by 4" rule is presented to approximate average marginal ...
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Relative Risk Constraint?
I am starting to dig into some epidemiology and am just starting to get into the nuances of relative risk (RR) vs. the odds ratio (OR). In the Fundamentals of Biostatistics, I read:
"Although ...
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Interpreting infinite odds ratio and confidence interval from Fisher's test
I've performed a two-sided Fisher's exact test on the following data, and the results include Infinity for the upper confidence interval and odds ratio. Are these results erroneous, and if not how do ...
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Interpretation of chisquare and odds ratio
I am studying te association between variables and used the chisquare test and the odds ratio of fisher exact test. I would like to know the exactly interpretation that i can do.
The main variable is ...
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Multiple risk ratio analysis or single multiple logistic regression for survey
I was asked by a doctoral student to analyze the answers to an old questionnaire her lab has and would like to publish the results of.
There are a few questions with regards to animal care and disease ...
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Comparing odds ratios of the same predictors and the same outcome across category of gender
I have two logistic models assessing the correlates of a binary outcome in males and females, respectively. The predictors are the same in both groups.
I want to see if the effects of the predictors ...
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Meta-analysis for case-control studies, confounding factors
Is there a way to adjust the pooled summary effect size (odds ratio) for confounding factors while performing a meta-analysis in R studio?
I am performing a meta-analysis and I don't want to pool ...
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What test to use to compare two proportions (and calculate effect size and confidence interval)?
There are many related questions here and elsewhere, but I found no satisfying answer.
There are plenty of related tests and concepts: Z-test, chi-squared test, G-test, McNemar's test, Fisher's exact,...
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Regarding interpretation of Odds Ratio
I have just read in my professor's lecture notes that the Odds ratio $\psi(x)$ takes non-negative values, and that the the effect of $X$ (the predictor) on $Y$ (the binary target variable) is measured ...
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Probability of association in logistic regression models
I’m using a logit model to evaluate the association of a set of habitats (H) to a particular land cover. Both land cover and H are binary variables.
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How does fisher.test calculate the confidence interval for the odds ratio in R?
The fisher.test function in base R by default returns a confidence interval for the odds ratio in a 2x2 contingency table. For example:
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Strange odds ratio (OR) derived from Fisher's test
I have frequency data for about 1000 genetic marker for two groups that I want to compare them between the two groups. I used Fisher’s test (in R) on the count data and got FDR and odds ratio (OR) for ...
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Creating a Weighted Ratio Based On Size of Customer
I am attempting to created a weighted ratio/score for customers based on the number of support tickets they have entered in a time period against the number of units they have in service with us.
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1D Bayesian Inference clarification
I'd like some help making sure I understand a 1D Bayesian inference problem.
Say I have a data vector which is an array of the number of flu cases reported weekly in California for the past 10 years.
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predict important markov chains(paths to an event) with confidence
I need help in validating my current approach as well as find any alternative approaches I could use in order to tackle issues like below.
I have a dataset like below and I need to find important ...
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Odds ratio not between the two odds ratio of a stratified analysis
This is not the first time I have performed stratified analyses based on logistic regressions, but I have never before been confronted with this situation.
When I test my relationship in the overall ...
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Odds Ratio, More Likely vs. As Likely, do I need to subtract 1?
When reporting odds ratios from a logistic regression, I've seen the words "as likely" and "more likely." If the odds ratio is say 3.5, I know that I can say females are 3.5 times as likely as males ...
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How to compare odds ratios across stratified sub-groups
From a randomized controlled trial, I have odds ratios (ORs) of disease A for an intervention vs control group.
I want to see if the OR differs according to deprivation.
I plan to stratify my study ...
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Interpretation of two odds ratios derived from two different cohen's ds, comparability for meta-analysis?
I have a question regarding the conversion of cohen's d into odds ratio (OR) and the comparability of results from two different situations. I wonder if the ORs derived from the two situations can ...
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reversal of odds ratios in covariate adjusted model
I am using a survey weighted GLM in R for a binary outcome. The raw risk ratio and the unadjusted ORs suggest that group 2 has significantly lower risk/odds. In the covariate adjusted model, the ...
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Converting OR to probabilities
I'm trying to understand some of my data in a logistic regression. I plotted headache (yes/no) vs. age and get an OR of 0.95.
Now I realize this means that for every year 'younger', you have a 0.95 ...
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Conclusion for not rejecting a null hypothesis
I'm actually quite confused what is the outcome we could deduce here for the other exercise types listed in the diagram.
From my interpretation, the null-hypothesis is: There is no association ...
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How does non-response bias affect the Confidence Interval
I asked earlier what is the idea behind putting up Table 3.
I have a follow up question on how non-response bias identified can justify the different sizes of Confidence Interval(CI) in Figure 3. My ...
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The effect of a lack of dose-response results on odds ratio
This is part of a quantitative reasoning assignment I was working on.
The study hypothesized that exercise may reduce the risk of disability for activities of daily living(ADL). However after ...
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Deriving the values of the range around the mean value
This is part of a bigger quantitative reasoning assignment I was working on.
My understanding here is that the upper bound and lower bound of the ranges for each of the exercises should be reflected ...
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How do I interpret the odds ratio of an interaction term in Conditional Logistic Regression?
I am wondering what the correct interpretation of the odds ratio of an interaction term in conditional logistic regression is.
Let's say there are two independent variables A and B, as well as an ...
